-LRB- CNN -RRB- -- Thirteen Boston deputy fire chiefs have signed a letter of `` no confidence '' in Fire Chief Steve Abraira regarding his handling of the Boston Marathon bombings , according to the letter , which CNN independently obtained from a deputy chief who signed it but requested anonymity .

The deputy chiefs wrote of their displeasure to Boston Mayor Thomas Menino on April 26 , according to the letter .

`` You can unequivocally consider this letter a vote of no confidence in Chief Abraira , '' the deputy chiefs wrote in the letter . They said the chief failed to assume command responsibility or show any leadership at the scene .

`` Despite the fact that the members of the BFD command staff have become accustomed to this ` ghost fire chief , ' nothing prepared us for his actions , actually inactions , on the day of the horrific terrorist attack at the Boston Marathon , '' the letter reads .

`` At a time when the City of Boston needed every first responder to take decisive action , Chief Abraira failed to get involved in operational decision-making or show any leadership , '' the letter continues .

In the letter , the deputies describe an e-mail that Abraira sent to all department members , saying that when he arrived at the scene , `` it was clear that our Command Officer had the incident well in hand and that our department was fully active in a support role with our law enforcement partners . ''

The deputies call Abraira 's argument `` illogical '' and `` mere rationalization to justify his behavior , '' saying that when Abraira arrived , the Boston Fire Department was `` still heavily involved in the incident '' because of the possibility of `` second explosions , '' `` additional suspicious packages '' and `` structural stability concern of buildings , '' among other issues .

But Abraira defended his actions to CNN .

`` In their estimation , they believe that if you do n't assume command , you do n't have responsibility there for what goes on , '' he said . `` I tried to explain to them , if I 'm on the scene , I 'm still responsible . That 's it . But they do n't believe it . ''

Boston 's top cop asked if bombing was preventable

The chief told The Boston Globe that he was comfortable with the way his commanders were handling the incident .

`` The nationally accepted practice is that you only take command -LRB- as chief -RRB- if there 's something going wrong or if you can strengthen the command position or if it 's overwhelming for the incident commander , and none of those things were in fact happening , '' he told the paper .

The president of the Boston City Council , Steve Murphy , told CNN Wednesday that he was at the finish line shortly after the bombings and `` personally I did n't see anything but selfless heroic acts on the part of the fire , EMT and police personnel . ''

But Murphy added , `` if all 13 of our district chiefs are expressing no confidence then that concerns me . '' He said if the mayor did not act in response to the letter that the City Council , which funds the fire department , would look into the functioning of fire department command during upcoming budget discussions .

The twin blasts at the end of the Boston Marathon on April 15 killed three people and wounded more than 260 others . Six people remained hospitalized Wednesday , according to a CNN count .

One of two bombing suspects , Tamerlan Tsarnaev , died after a gunfight with authorities four days later . After much secrecy and protest , he was buried in a rural Virginia cemetery this month .

To locals ' surprise , Tamerlan Tsarnaev buried in Virginia cemetery

Police took his brother , Dzhokhar Tsarnaev , into custody on April 19 after finding him hiding in a boat in the backyard of a Watertown , Massachusetts , home .

He has been charged with using a weapon of mass destruction and malicious destruction of property causing death .

Tsarnaev is being held at Federal Medical Center Devens .

Source : Russia withheld details about Tsarnaev

CNN 's Joe Sterling and Lawrence Crook III contributed to this report .

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NEW : Letter says chief was n't `` involved in operational decision-making , '' did n't show leadership

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Chief defends his actions to CNN , says incident was `` well in hand '' when he arrived

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Source : Nearly all of Boston 's deputy fire chiefs sign letter of `` no confidence ''

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The Boston Marathon bombing killed three and wounded more than 260 others